What are the Key Phenomenological Clues to Diagnose Functional Tic‐Like Behaviors in the Pandemic Era?

Abstract

BackgroundFunctional tic‐like behaviors (FTLBs) can be difficult to distinguish from tics.ObjectivesTo describe the phenomenology of FTLBs in youth and assess the movements and vocalizations most suggestive of the diagnosis.MethodsWe compared the phenomenology of tics between youth (<20 yr) with FTLBs and with primary tics from our Registry in Calgary, Canada.ResultsTwo hundred and thirty‐six youths were included: 195 with primary tics (75% males; mean age: 10.8 yr) and 41 with FTLBs (98% females; 16.1 yr). In the bivariate models, FTLBs were most associated with copropraxia (OR = 15.5), saying words (OR = 14.5), coprolalia (OR = 13.1), popping (OR = 11.0), whistling (OR = 9.8), simple head movements (OR = 8.6), and self‐injurious behaviors (OR = 6.9). In the multivariable model, FTLBs were still associated with saying words (OR = 13.5) and simple head movements (OR = 6.3). Only 12.2% of youth with FTLBs had throat clearing tics (OR = 0.2).ConclusionsThis study shall help physicians diagnose youth with FTLBs according to the presence/association of specific movements and vocalizations.

Functional Tic-like Behaviors: From the COVID-19 Pandemic to the Post-Pandemic Era

“…The timeframe of the studies spans four years (between 2021 and 2024), and the geographic distribution is skewed towards North America, where the majority of the studies took place. Specifically, five studies were conducted in Canada [ 32 , 33 , 39 , 41 , 42 ], two each in Germany [ 31 , 40 ] and in the United States [ 35 , 37 ], and one each in Australia [ 34 ], Denmark [ 36 ], and the United Kingdom [ 38 ]. All studies were conducted within specialist clinic settings.…”

“…In a similar study conducted on a German sample ( n = 32), half of the patients with functional tic-like behaviors were males and were not more likely to present with co-morbid anxiety and depression than patients with neurodevelopmental tics [ 40 ]. Finally, three studies were recently conducted at the same specialist clinic in Canada on 35 [ 39 ], 40 [ 42 ], and 41 [ 41 ] adolescents and young adults with functional tic-like behaviors, respectively. In addition to confirming a significantly higher proportion of females with older age at symptom onset, these studies found that patients with functional tic-like behaviors were more likely to present with anxiety and depression [ 39 ], to be gender-diverse individuals [ 42 ], and to report coprophenomena, popping, whistling, simple head movements, and self-injurious behaviors [ 41 ] than patients with neurodevelopmental tics.…”

“…Finally, three studies were recently conducted at the same specialist clinic in Canada on 35 [ 39 ], 40 [ 42 ], and 41 [ 41 ] adolescents and young adults with functional tic-like behaviors, respectively. In addition to confirming a significantly higher proportion of females with older age at symptom onset, these studies found that patients with functional tic-like behaviors were more likely to present with anxiety and depression [ 39 ], to be gender-diverse individuals [ 42 ], and to report coprophenomena, popping, whistling, simple head movements, and self-injurious behaviors [ 41 ] than patients with neurodevelopmental tics. Since all controlled studies were conducted in specialist clinics, referral bias needs to be taken into account when interpreting their findings, with regard to both cases with functional tic-like behaviors and controls with neurodevelopmental tics.…”

“…Case series providing accurate clinical descriptions of functional tic-like behaviors and studies comparing their phenomenology with that of neurodevelopmental tics provided initial data suggesting differences in the characteristics of the tic repertoire. The phenomenological features of functional tic-like behaviors tend to involve specific complex movements/actions, often including (self) hitting [ 27 , 32 , 35 , 36 , 38 ], throwing objects [ 25 , 27 , 32 , 38 ], or freezing/motor blocking [ 35 , 38 , 41 ]. This contrasts with the higher prevalence of simple motor tics in patients with Tourette syndrome and other neurodevelopmental tic disorders, especially in the early stages of the condition [ 55 , 56 ].…”

“…The clinical phenotypes of patients with onset of functional tic-like behaviors during the pandemic have been documented in reports from the United States [ 22 , 23 ], the United Kingdom [ 24 , 25 , 26 ], and multiple European countries [ 27 , 28 , 29 ], as well as a multi-national registry collating data from ten specialist centers across North America, Australia, and Europe [ 30 ]. Moreover, phenotypical differences between patients with functional tic-like behaviors and patients with neurodevelopmental tics have been explored in multiple controlled studies from the same three continents [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ].…”